LTC4449

10

4449f

APPLICATIONS INFORMATION

Bypassing and Grounding

(nanoseconds) and large AC currents (amperes). Careless

component placement and PCB trace routing may cause

excessive ringing and under/overshoot.

To obtain the optimum performance from the LTC4449:

• Mount the bypass capacitors as close as possible

pins, and the BOOST and TS pins. The leads should

be shortened as much as possible to reduce lead

inductance.

• Use a low inductance, low impedance ground plane

to reduce any ground drop and stray capacitance.

Remember that the LTC4449 switches greater than

5A peak currents and any significant ground drop will

degrade signal integrity.

• Plan the power/ground routing carefully. Know where

the large load switching current is coming from and

going to. Maintain separate ground return paths for

the input pin and the output power stage.

• Keep the copper trace between the driver output pin

and the load short and wide.

• Be sure to solder the Exposed Pad on the back side of

the LTC4449 packages to the board. Correctly soldered

to a double-sided copper board, the LTC4449 has a

thermal resistance of approximately 64°C/W. Failure

to make good thermal contact between the exposed

back side and the copper board will result in thermal

resistances far greater.